Light Emitting Diode (LED) technology is now internationally accepted as having many advantages for residential, commercial, industrial and institutional illumination due to high efficiency over more standard lighting technologies, such as incandescent light bulbs. In fact, governments around the world have passed measures to phase out incandescent light bulbs for general lighting in favor of more energy-efficient lighting alternatives. Phase-out regulations effectively ban the manufacture, importation or sale of incandescent light bulbs for general lighting, incandescent lamps being presently one of the most inefficient light sources in use.
A LED module is an assembly of an array of individual LEDs or LED chips used to produce higher output illumination than would be possible with a single LED. Moreover, a LED module is often more compact than an array of individual LEDs and is often packaged to enable easy installation onto a heat sink or metal assembly of a lighting fixture or luminaire. There are many types of LED modules in the market place. Some are single color for traffic lights or for signs, warning lights and other similar applications, and others are “white” LEDs specifically intended for illumination purposes to substitute or replace conventional lighting sources such as, but not limited to, fluorescent lamps, fluorescent tubes, incandescent lamps and arc-discharge lamps, among others.
While LED modules are widely used today, they require thermal management to ensure that recommended operating temperatures are not exceeded and also often require to be protected against environmental influences such as water, ice, dust, other air borne particles, and smoke, among others. For thermal management and protection against environmental influences, the user must use suitable protection hardware and covers which add significant cost and require significant engineering skills for guaranteed operational longevity.
One manner of providing such protection would be to encapsulate the LED module. However, such encapsulation has two major issues. First, encapsulation typically changes the correlated color temperature (CCT) of the LED module, which may thus produce light that is not suitable, or at least less suitable, for its intended purpose. Second, encapsulation may reduce heat transfer from the LED module to the environment, which increases the temperature of the LEDs and thus shortens their lifespan.
In addition, LED module manufacturers usually offer very limited performance guarantees due to unknown end user applications, which are known, to misuse/abuse the LED modules by exceeding recommended operating conditions. Moreover, due to unknown operating conditions, the LED module manufacturer cannot offer or guarantee exact performance specifications such as efficacy in Lumen/Watt, chromaticity, lumen maintenance and other performance and fixture parameters, such as, but not limited to end luminaire CCT (Correlated Color Temperature) and CRI (Color Rendering Index).
As with many other light sources such as fluorescent lamps and arc-discharge lamps, LEDs and LED modules require a CC (constant current) or, CP (constant power source), or a characteristic between the two. These “power sources” are called “drivers” and are usually DC (Direct Current) provided by efficient high frequency power supply technology such as SMPS (Switched Mode Power Supplies) or RMPS (Resonant Mode Power Supplies). Most LED drivers are isolated since known LED modules do not comply with International “Double Insulation System” safety standards, so that the safety aspects usually have to be implemented into the drivers.
In addition to the above restrictions, LED modules operate usually at low voltage to enable the user to buy “off the shelf” drivers complying with international safety regulations and outputting voltages within SELV (Safe Extra Low Voltage) levels enabling easy installation and certification to safety standards well-known in the industry. These low voltages are in fact problematic for many high power LED modules making it difficult for strings of parallel and series LED elements or modules to current share correctly for an extended period of time, thus often causing premature failure due to thermal runaway and ‘current hogging’ reasons
Thus, current LED module technology has limitations of isolation, good thermal conduction properties and also a lack in proper hermetic sealing due to technical difficulties of manufacturing a sealed LED module. It is also well known in the art that coating a LED can cause severe spectral and illumination changes and losses due to scattering and diffraction.
Accordingly, there exists a need for improved LED modules. It is a general objective of the present invention to provide such an improved LED module.